document.write( "Question 133204: rema is older than ken. the difference of their ages is 12 and the sum of their ages is 50. find the age of each \n" ); document.write( "
Algebra.Com's Answer #97405 by jim_thompson5910(35256)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "If \"the difference of their ages is 12\", then the first equation is \"x-y=12\". Also, if \"the sum of their ages is 50\", then the second equation is \"x%2By=50\".\r
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\n" ); document.write( "\n" ); document.write( "So let's solve this system by using substitution\r
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\n" ); document.write( "\n" ); document.write( "Start with the given system of equations:\r
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\n" ); document.write( "\n" ); document.write( "\"system%28x-y=12%2Cx%2By=50%29\"\r
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\n" ); document.write( "\n" ); document.write( "Now in order to solve this system by using substitution, we need to solve (or isolate) one variable. I'm going to solve for y.\r
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\n" ); document.write( "\n" ); document.write( "So let's isolate y in the first equation\r
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\n" ); document.write( "\n" ); document.write( "\"x-y=12\" Start with the first equation\r
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\n" ); document.write( "\n" ); document.write( "\"-y=12-x\" Subtract \"x\" from both sides\r
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\n" ); document.write( "\n" ); document.write( "\"-y=-x%2B12\" Rearrange the equation\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28-x%2B12%29%2F%28-1%29\" Divide both sides by \"-1\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28%28-1%29%2F%28-1%29%29x%2B%2812%29%2F%28-1%29\" Break up the fraction\r
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\n" ); document.write( "\n" ); document.write( "\"y=x-12\" Reduce\r
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\n" ); document.write( "\n" ); document.write( "Since \"y=x-12\", we can now replace each \"y\" in the second equation with \"x-12\" to solve for \"x\"\r
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\n" ); document.write( "\n" ); document.write( "\"x%2Bhighlight%28%28x-12%29%29=50\" Plug in \"y=x-12\" into the first equation. In other words, replace each \"y\" with \"x-12\". Notice we've eliminated the \"y\" variables. So we now have a simple equation with one unknown.\r
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\n" ); document.write( "\n" ); document.write( "\"2x-12=50\" Combine like terms on the left side\r
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\n" ); document.write( "\n" ); document.write( "\"2x=50%2B12\"Add 12 to both sides\r
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\n" ); document.write( "\n" ); document.write( "\"2x=62\" Combine like terms on the right side\r
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\n" ); document.write( "\n" ); document.write( "\"x=%2862%29%2F%282%29\" Divide both sides by 2 to isolate x\r
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\n" ); document.write( "\n" ); document.write( "\"x=31\" Divide\r
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\n" ); document.write( "\n" ); document.write( "-----------------First Answer------------------------------\r
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\n" ); document.write( "\n" ); document.write( "So the first part of our answer is: \"x=31\"\r
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\n" ); document.write( "\n" ); document.write( "Since we know that \"x=31\" we can plug it into the equation \"y=x-12\" (remember we previously solved for \"y\" in the first equation).\r
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\n" ); document.write( "\n" ); document.write( "\"y=x-12\" Start with the equation where \"y\" was previously isolated.\r
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\n" ); document.write( "\n" ); document.write( "\"y=%2831%29-12\" Plug in \"x=31\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=31-12\" Multiply\r
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\n" ); document.write( "\n" ); document.write( "\"y=19\" Combine like terms \r
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\n" ); document.write( "\n" ); document.write( "-----------------Second Answer------------------------------\r
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\n" ); document.write( "\n" ); document.write( "So the second part of our answer is: \"y=19\"\r
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\n" ); document.write( "\n" ); document.write( "-----------------Summary------------------------------\r
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\n" ); document.write( "\n" ); document.write( "So our answers are:\r
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\n" ); document.write( "\n" ); document.write( "\"x=31\" and \"y=19\"\r
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\n" ); document.write( "\n" ); document.write( "So the two ages are 31 and 19
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